The basics of quantum physics

By Adam Bitton, Aug 23, 2017

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Say the words ‘quantum physics’ to almost anyone, and they’ll feel lost and confused straight away. It really is quite a daunting subject! However, it doesn’t have to be. It can be explained by stripping it right back to basics, easily enough for anyone to understand!

What does quantum physics mean?

Quantum physics is all about matter and energy; the matter and energy of everything in the universe. That’s one of the cool things about physics – it doesn’t just apply to things we can see and touch, we can make calculations and create understanding about stars billions of light years away because they will follow the same rules. This particular branch of science is all about the different behavior and characteristics of the smallest units in existence, atoms and subatomic particles, to assist studies into the nature of the universe regarding matter and energy.

When was it first discovered?

The quantum theory first came about in the year 1900. The theory was presented to other renowned scientists by Max Planck, a German physicist. He proposed the idea that energy acted in a similar way to matter and is therefore quantifiable. He also went on to propose that all forms of matter have a relationship with energy, being able to both absorb and emit it.

Einstein and Schrödinger

A few years later, Albert Einstein (now one of the most famous scientists in the world) said that he believed that not only were energy and matter quantifiable, but so was radiation. Through this discovery, he managed to discover a new equation to work out how quickly energy traveled, how fast the speed of light was, and the frequency of both too. The final stage of this was Einstein discovering that energy could move both as waves and as particles.

Even further down the line, another scientist – Erwin Schrödinger – made a discovery called the wave equation which further explained the movement of energy and matter as waves. Imagine plucking a guitar string; the string moves up and down, traveling down the length of the string from where it was plucked. This is a wave, and is the same principle as magnetic waves, waves of light and water waves. While another scientist, Werner Heisenberg, proposed something known as the ‘uncertainty principle’ to conflict with Schrodinger’s discovery, it is still widely worked with today.

What do we know now?

Now, in the 21st century, we have developed our understanding of quantum physics quite drastically. We have come a long way from the original discoveries of the scientists mentioned above, and now we know that energy exists in small ‘packets’, which are referred to as quanta. We also now know that energy is discontinuous, meaning that it can only be at distinct levels; not in-between as a complete range. Subatomic particles act in the same way particles and waves would but on a much smaller scale.

What can quantum physics be used for?

There are many aspects of technology we use today in the modern world that operate on such a small scale that the micro effects seen in quantum physics are hugely important in their function. A lot of electronic devices were designed and built using quantum physics, such as the microchip used in almost every computer and smartphone on the planet. Quantum physics is of great importance in medical research and imagery such as the electron microscope and magnetic resonance imaging (MRI). Quantum physics has been used in all aspects of modern life, from computers and telephones, to the simple light switch.

As an ever evolving branch of science, quantum physics is still one of the most important theories that has ever been proposed to the rest of the world. It added a whole new dimension to the world of science and knowledge – specifically, the world of physics and the understanding of nature and our universe – and there is absolutely no doubt that our world would be quite different without the discovery of it.